This invention relates in general to methods and devices for breathing assistance.
More precisely, the invention relates to a breathing assistance device comprising:                a turbine to generate a flow of pressurised respiratory gas,        a duct to carry the pressurised gas to a patient,        means for controlling the gas pressure capable of elaborating a pressure setting for the turbine.        
And the invention also relates to a method for regulating the pressure of a respiratory gas delivered by a turbine to a patient, the method consisting of elaborating a pressure setting for the turbine.
Devices of the type mentioned above already exist.
The basic architecture of such devices is shown in a very schematic manner in FIG. 1a, which shows a device 10a consisting of a turbine 100a allowing to generate a flow of pressurised respiratory gas (air or other), a means 120a allowing a patient to receive said pressurised gas and a duct 110a to carry the gas from the turbine 100a to means 120a. 
Means 120a is generally made up of a mask that can include vents to make respiratory gas leaks possible.
Note that this means can be replaced with an expiratory valve.
And the invention applies to devices with leakage masks as well as to expiratory valve devices.
Note that the term “patient” is here used broadly, and does not necessarily correspond to a person afflicted with an extensive pathology.
The devices according to the invention can thus be implemented for numerous applications, for example to provide respiratory assistance while a patient is sleeping with a view to treating sleep apnea.
However, the devices according to the invention are not in any way limited to treating sleep apnea, which is an application of the invention mentioned here by way of non-limitating example.
The invention relates to in fact as we shall see a new type of device and associated regulation, and its applications are extremely broad.
Returning to the device of the state of the art shown in FIG. 1a, such devices are known to be implemented by controlling the pressure generated by turbine 100a in such a way that this pressure has a fixed value.
Such devices are said to be of the continuous pressure airway pressure type (and are generally known under the acronym of CPAP-Trade Mark-in English).
These devices may however not be accepted by a portion of the patients, or be improperly adapted for treating certain pathologies.
More elaborate devices also exist, in which the means of controlling gas pressure are capable of elaborating several different pressure settings for the turbine.